Calbindin D-28k immunoreactivity in the temporal neocortex in patients with Alzheimer's disease.

Calbindin D-28k immunoreactivity in the temporal isocortex was examined in seven patients with Alzheimer's disease (AD) and in six controls. In normal brains, calbindin D-28k-immunoreactive cells were bitufted neurons, multipolar cells with ascending dendrites and large double-bouquet cells mainly located in layers II and III. Immunoreactive fibres were seen in the molecular layer and in vertical bundles in layers III and V/VI. Calbindin D-28k immunoreactivity was reduced in patients with AD, although with differences from one patient to another. Immunoreactivity was decreased in the plexus of the molecular layer and in the vertical bundles in the cellular layers in every case. Most patients had, also, decreased immunoreactivity in the dendritic arbors. The number of calbindin D-28k-immunoreactive cells was significantly decreased in three of five patients with moderate or severe dementia, and was normal in two cases with mild dementia.